Various devices have been proposed in recent years to cope with the increasingly difficult problem of handling garbage and refuse material generated by residents living in an urban area. It is convenient here for the reader to refer, for example, to U.S. Pat. No. 3,384,007 which issued May 21, 1968 to Boje et al; U.S. Pat. No. 3,669,009 which issued June 13, 1972 to Pratt et al; or U.S. Pat. No. 3,685,438 which issued Aug. 22, 1972 to W. E. Ziegler. Two additional patents which show similar structures are Canadian Pat. Nos. 905,210 and 914,483 of Longo which issued respectively, on July 18 and Nov. 14, of 1972. In the Canadian Pat. No. 914,483, a compaction device is shown for compressing household refuse. Pressure used to drive a compression ram is derived from a municipal water supply. This water is introduced into an extensible bellows which cases a ram to advance and compact refuse ahead of it. The structure of this patent does not use that water pressure for retracting the ram elements, and instead, relies upon forces derived from a high tension helical spring. The other Canadian patent mentioned above, namely, 905,210 also shows a waste compacting device. This device includes a horizontally extending compression chamber which includes an upwardly facing feed opening for receiving waste material. A ram which comprises a transverse plate and a horizontally oriented gate-defining plate are moveable under the effect of a double acting hydraulic cylinder. A four-way valve is used to direct the hydraulic fluid to the appropriate side of the hydraulic cylinder, thereby to cause either retraction or advancement of the ram.
U.S. Pat. No. 3,669,009 of Pratt et al. discloses a compacting device for household trash and garbage. This trash compactor features a double-acting piston which is advanced and retracted under the effects of hydraulic pressure derived from a home water system. It will be seen, however, that the movable piston in this device carries an elongated plate which acts as a ram to compress the refuse material ahead of it. Substantial bending moments can be generated by the overhang of the opposed end portions of the ram plate relative to the connection of that plate to the movable piston. Thus, the uniform distribution of cans, bottles or other solid items in the compression chamber is important for optimum efficiency in operation.
Certain of the other prior art patents referred to require a piston and cylinder combination which uses conventional hydraulic fluids and reservoirs, and clearly necessitates the extra cost in providing equipment such as a driving motor and pump. Further yet, the pressure capability of such pumps must be substantial, and this incurs extra expense.